Hypodermic syringe.



PATENTED DEC; 29, 1903.

A. SCHMIDT. HY'PODERMIG SYRINGE.

APPLICATION FILED MAY 25. 1903.

N0 MODEL.

jighi UNITED. STATES Patented December 29, 1903.

PATENT OFFICE.

I ARNQ SCHMIDT, OF WEIMAR, GERMANY.

HYPODERMIC SYRING E.

SPECIFICATION forming part of Letters Patent N 0. 748,424, datedDecember 29, 1903. Application filed May 25, 1903... Serial No. 158.736.(No model- To all whom it may concern:

Be it known that LARNO SCHMIDT, a subject of the Grand Duke ofSaxe-Weimar, residing at Weimar, in the Grand Duchy of Saxe-Weimar,German Empire, have invented certain new and useful Improvements inHypodermic Syringes, of which the following is a specification.

My invention relates to improvements in syringes. Hitherto the syringesin use for hypodermic injections if in order to charge the syringe theliquid was poured into the tube-that is to say, if it was not preferredor not preferable to charge it by suctionthe cannula or the nozzle forthe insertion of the needle had to be held closed. The piston wasthereupon inserted. This is laborious, on the one hand and, on the otherhand, in either case, air-bubbles are likely to be formed in the liquid,which cannot be avoided and which, as is well known, may be veryinjurious to the patient. To avoid these evils and to provide a syringefor hypodermic injections or the like made entirely of glass or thelike, and therefore completely aseptic and easy to manipulate as well asto clean, is the object of my invention.

The annexed drawings show the syringe described on an enlarged scale,wherein- Figure 1 is a longitudinal section of the syringe with thepiston pushed home completely. Fig. 2 is a cross-section.

The syringe according to my invention consists of a tube a, closed atone endthat is to say, without cannula'and open at the other end, atwhich the piston b, contrary to the arrangement adopted in the syringeshitherto in use, carries the cannula c and at its outer end a nozzle dfor the insertion of a hollow needle of any known form. The piston 12 iscarefully ground into the tube and accurately covers with its inner endface f the bottom of the tube, which is graduated in the known manner,so that the tube is completely discharged.

. up to the desired graduation-line.

The syringe is charged either by immersing the outer end of the pistonin the liquid and withdrawing the tube, whereby the liquid is suckedinto the tube, completely filling the existing cavity Without formingany air-bubbles, or on removing the piston from the tube the liquid maybe poured direct into the tube I Thereupon the piston is reinserted inthe tube and any air remaining in the interior of the tube and piston isexpelled through the cannula. Thus injections may be made in the mostconvenient mannerand without keeping the tube closed in order to chargeit in any mannerfor instance, with the finger-and without any risk ofintroducing air into the system of the patient through the syringe.

Having now particularly described and ascertained the nature of myinvention and in what manner the same is to be performed, I declare thatwhat I claim is 1. A syringe consisting of a tube and a pist-on, both ofglass and in a single piece, one end of the tube being closed, and thepiston having a cannula extending entirely through the same and alsofitting throughout its entire length closely within the tube.

2. A syringe consisting of a tube and a piston, both of glass, and in asingle piece, one

end of the tube being closed, and the piston' having a cannula extendingentirely through the same and of approximately equal diameter throughoutits length, said piston fitting throughout its entire length closelywithin the tube.

In testimony whereof I have hereunto set my hand in presence of twosubscribing wit nesses.

ARNO SCHMIDT.

Witnesses:

CARL OTTO WILLIAM KARST, ALBERT LoUIs MAX REIoH.

